GB 31421-2025 Head protection—Occupational antistatic headwear English, Anglais, Englisch, Inglés, えいご
This is a draft translation for reference among interesting stakeholders. The finalized translation (passing thorugh draft translation, self-check, revision and varification) will be delivered upon being ordered.
ICS 13.340.20 CCS C 73
NATIONAL STANDARD OF THE PEOPLE'S REPUBLIC OF CHINA
GB 31421-2025
Replaces GB/T 31421-2015
Head protection-Occupational antistatic headwear
Issued on 2025-08-29
Implemented on 2026-09-01
Issued by State Administration for Market Regulation
Standardization Administration of China
Content
Foreword
1 Scope
2 Normative references
3 Terms and definitions
4 Specifications, dimensions, and designs
4.1 Specifications and dimensions
4.2 Structural designs
5 Technical requirements
5.1 General requirements
5.2 Fabric
5.3 Finished products
6 Test methods
6.1 General test methods
6.2 Fabric physicochemical test methods
6.3 Finished product test methods
7 Marking
7.1 Permanent markings
7.2 Compliance certificates
7.3 Product manuals
8 Packaging, storage, and cleaning
Appendix A (Normative) Surface resistivity test method
A.1 Principle
A.2 Equipment
A.3 Washing and conditioning
A.4 Specimens or garments
A.5 Test conditions
A.6 Test procedures
A.7 Result calculation
References
1 Scope
This document specifies the technical requirements, marking, packaging, storage, and cleaning of antistatic work caps, as well as the corresponding test methods.
It applies to work caps made primarily of antistatic fabric for workplaces with electrostatic discharge risks.
It does not apply to caps made mainly of nonwoven materials.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute essential requirements. For dated references, only the cited version applies. For undated references, the latest version (including amendments) applies.
GB/T 2912.1: Determination of formaldehyde in textiles - Part 1: Free and hydrolyzed formaldehyde (water extraction method)
GB/T 3917.3: Tear properties of fabrics - Part 3: Determination of tear force of trapezoid specimens
GB/T 3920: Textiles - Tests for color fastness - Color fastness to rubbing
GB/T 3921: Textiles - Tests for color fastness - Color fastness to washing
GB/T 3922: Textiles - Tests for color fastness - Color fastness to perspiration
GB/T 3923.1: Textiles - Tensile properties of fabrics - Part 1: Determination of breaking force and elongation at break (strip method)
GB/T 5453: Textiles - Determination of the permeability of fabrics to air
GB/T 7573: Textiles - Determination of pH of aqueous extract
GB/T 8427: Textiles - Tests for color fastness - Color fastness to artificial light: Xenon-arc
GB 12014-2019: Protective clothing - Antistatic clothing
GB/T 12703.1: Textiles - Test methods for electrostatic properties - Part 1: Corona charging method
GB/T 14576: Textiles - Tests for color fastness - Color fastness to light and perspiration
GB/T 17592: Textiles - Determination of azo colorants
GB 18401-2010: General safety technical code for textile products
GB 20097: General technical specifications for protective clothing
GB/T 21196.2: Textiles - Determination of abrasion resistance of fabrics using Martindale apparatus - Part 2: Determination of specimen breakdown
GB/T 23344: Textiles - Determination of 4-aminoazobenzene
FZ/T 01030: Knitted fabrics and elastic woven fabrics - Determination of seam strength and expansion - Bursting metho
3 Terms and definitions
The following terms and definitions apply to this document.
3. 1
Anti static work cap occupational Lantistaticchaadwear
A work cap made primarily from anti-static fabric to prevent the accumulation of static charges on the cap body.
three point two
Head circumference, head girl
The maximum circumference of the head measured horizontally above both ears.
Note: Refer to Figure 1 in GB/T 16160-2017.
three point three
Surface resistivity
The ratio of the potential gradient parallel to the direction of current passing through the surface of a material to the current per unit width of the surface, i.e. the direct current resistance between two pairs of sides of a square material per unit area.
Note: Unit: Ω/□.
three point four
Half half-life; HDT
The time required for the applied voltage to decay to half of the peak voltage on the sample.
4 specifications, dimensions, and structural styles
4.1 Specifications and Dimensions
The net size of the human head circumference is used as the specification size of the anti-static work cap, measured in centimeters (cm). The specification of the anti-static work cap is set to 44 cm~64 cm, with a jump of 1 cm.
4.2 Structural Style
4.2. 1. A dome shaped brimless hat with a brimless design that covers the entire head. Some styles have breathable mesh holes on the top or sides.
4.2.2 brimmed dome hat, with added brim design on top of the dome hat, can block sunlight or lighting, suitable for work environments that require visual protection.
4.2.3 A brimmed duckbill hat with a hard front brim and built-in conductive fibers to enhance static dissipation performance, suitable for outdoor work, and balancing sun protection and anti-static functions.
4.2.4 Shawl hat (head cap), covering the head, neck to shoulders, with a cross shaped magic tape or tie at the back neck to adjust the tightness, and some styles integrate ear nets or masks.
5 Technical Requirements
5.1 General Requirements
5. 1. 1 Appearance quality
5. 1. one The appearance of the anti-static work cap should be free of damage or other defects that affect its anti-static performance.
5. 1. 1.2 There are no obvious oil stains, disassembly marks, residual defects, or hair leaks in any part.
5. 1. 1.3 Anti static work caps should not come with metal accessories. If necessary, metal accessories should not be directly exposed.
5.1.2 Sewing
5. 1.2. The stitch spacing should be between 12 stitches/3cm and 16 stitches/3cm.
5.1.2.2 The tightness of the upper and lower parts is appropriate, with no jumping or broken needles, and there should be a return needle at the lifting needle position.
5.1.2.3 The thread should be evenly distributed, and the same component should not have more than two missing needles or two locations.
5.1.2.4 The elastic band should be moderately tight, and the strap should be tight.
5.1.2.5 Permanent markings should be firmly sewn onto the product itself.
5.2 Fabric
Press 6 2. Conduct testing, and the physical and chemical properties of the fabric should meet the requirements specified in Table 1.
Table 1 Technical Requirements for Cooking and Chemical Properties of Noodles
5.3 Finished products
Press 6 3. Conduct testing and ensure that the physical and chemical properties of the finished product meet the requirements specified in Table 2.
Table 2 Technical Requirements for Physical and Chemical Properties of Finished Products
6 Testing Methods
6.1 General Requirements Testing Methods
6. 1. 1. Appearance quality testing method: visually inspect the entire surface, lay the hat flat or cover it on a standard head mold, and sequentially inspect the inner and outer surfaces of the hat top, hat body, hat brim (if any), and shawl (if any), recording whether there are exposed metal accessories and defect types (damage, residue, stains, creases, hair leakage, yarn breakage, yarn jumping, etc.).
6.1.2 Sewing Requirements Testing Method: Full seam inspection, lay the hat flat or cover it on the head mold, observe all sewing seams section by section (including the top seam of the hat, the side seam of the hat body, the connection seam between the hat brim and the hat body, the edge seam of the shawl, the seam of the elastic band, etc.), and record the type of defect (jumping needle, broken thread, missing seam, floating thread); And select 3 cm long stitches at 3 different suture sites, avoiding the starting/ending points. Use a ruler to count the number of stitches within 3 cm (needle spacing=number of stitches/3 cm), measure 3 times at each site, take the average value, and round the average value to an integer (rounding).
